The invention relates to a device for starting a motor vehicle with an electronic key. Such devices are conventionally referred to as xe2x80x9celectronic ignition lockxe2x80x9d or xe2x80x9cignition and steering column lockxe2x80x9d. Conventionally, by means of an electronic key, the access to the vehicle is locked and unlocked. For this purpose suitable door locks are provided. When employing these keys in the device of interest in this connection, the key is inserted into a receptacle provided in the motor vehicle. In certain situations a cover provided thereat is pushed out of the way. For controlling different functions within the motor vehicle the inserted key is moved into various key positions within the receptacle.
In the known device of this kind (DE 44 34 655 A1), the different functions are selected by means of corresponding rotational positions of the electronic key in the receptacle. For this purpose, the receptacle is comprised of a rotor and a stator and different sensors on the stator which must determine the different rotational positions of the rotor. This is complex with regard to construction and requires a large space. In order to exert the required torque for adjusting the key manually, the key must project sufficiently far out of the opening of the receptacle. A key which projects far however increases the risk of injury in a crash situation of the vehicle. In addition or as an alternative to the rotating movement, a transitory movement of the key may also be performed.
In a device of a different kind (DE 198 14 964 A1) the signal for authorizing driving is generated by detection of a fingerprint of the authorized person. In this connection, an authorizing element in the form of a check card is used which is inserted into a slot adjacent to a toggle switch or a rotary switch. The rotary switch or the toggle switch have sensors for the fingerprint and can be pressure-actuated or rotated between different switch positions. Accordingly, different functions of the motor are controlled. In this case, in addition to the insertion movement of the authorizing element, a rotation or push movement of a switch as well as the application of a fingerprint at the location having the sensor are required. This complex actuation is cumbersome.
Finally, it is known in regard to a starter switch of a motor vehicle (DE 195 04 991 C1) to provide a shaft in a rotary handle for complete insertion of an identification card. This insertion is possible only in a first position of the rotary handle. Starting from this position, the rotary handle with inserted card can then be moved into different further rotational positions which control different functions of the motor. In this case, aside from the insertion movements, rotational movements of the rotary handle are also required.
Moreover, from DE 33 06 863 a device for starting a motor of a motor vehicle by means of an electronic key is known. The electronic key is longitudinally movable between several axially staggered stroke positions, wherein the electrical contacts, in cooperation with a sending-receiving unit, activate different functions in the individual stroke positions. The electronic key is secured in the stroke positions by snap-in locking action or by a manually pivotable locking lever. A disadvantage is that for the sequentially occurring working steps a different stroke position is required, respectively. Moreover, for starting the motor with this device, after insertion of the electronic key up to the end position, the electronic key must be held under pressure in the end position until the motor runs. This manipulation is somewhat cumbersome. The correlation of a working step with a stroke position of the electronic key also leads to this device having a correspondingly large size.
It is an object of the invention to provide a device of the kind mentioned in the preamble of claim 1 that is reliable and can be actuated comfortably and avoids the aforementioned disadvantages. This is achieved according to the present invention by the features of the characterizing portion of claim 1 which have the following special meaning.
According to the invention, the key is not rotated for selecting a function. The key is moved instead upon insertion into the receptacle into three stroke positions which are axially staggered relative to one another. Of these positions, the second stroke position is decisive for the ignition of the motor. In this second stroke position, the key is almost completely inserted into the receptacle. In this second stroke position and in the third, deeper, stroke position, the important functions within the motor vehicle are carried out, for which purpose, as needed, further manual or pedal-type actuators may be used. The motor vehicle operator must not carry out actuations with the key in order to trigger the desired functions within the motor vehicle. The key remains instead substantially immersed in the receptacle so that in a crash situation no risk of injury is to be expected as in the situation with projecting key parts.
In its second stroke position, the key is fixed in the receptacle by a directional lock whose positive-locking securing means secure the key relative to an axial spring force. In order to be able to remove the key again, it is sufficient to tap against its end. This transfers the key into its third stroke position. The end of the key can be immersed to any random depth within the receptacle. In this third stroke position, the locking action can be released as needed. The key is then pushed back into its initial position by means of an axial restoring spring action acting indirectly or directly on it. Now only a non-positive connection of a snap-in lock is present. The key can again be removed manually. According to the invention, only axial movements of the electronic key are thus required between at least three stroke positions in order to control the motor or further auxiliary devices within the motor vehicle. This axial movement is oriented in the same direction as the insertion of the key into the receptacle of the motor vehicle. Accordingly, a very obvious manipulation of the key is provided with the device of the invention.